Product Analytics for Next.js: What to Track and How to Actually Use the Data

Most developers launch products without an analytics setup. Then they wonder why some pages convert and others don't. Here's how to add meaningful analytics to a Next.js app -- tracking what actually matters, not just page views. What to Track Don't track everything . Tracking noise obscures signal. Track these four things: Funnel events : Landing page view -> Pricing view -> Checkout start -> Purchase complete Feature usage : Which parts of your app users actually use Error events : Where users hit errors or dead ends Revenue events : Tied directly to Stripe webhooks Option 1: PostHog (Recommended for Most Projects) PostHog is open-source, self-hostable, and has a generous free tier. It covers analytics, session recordings, feature flags, and A/B testing. npm install posthog-js posthog-node // src/lib/analytics.ts import { PostHog } from " posthog-node " // Server-side client (for API routes and Server Components) export const posthog = new PostHog ( process . env . NEXT_PUBLIC_POSTHO